Structure and floristic composition of the vascular epiphyte component of a subtropical ombrophilous alluvial forest located along the Barigüi river, Southern Brazil (25º34' S and 49º20' W) is described. The qualitative survey was carried out in an8.6 ha area while the quantitative survey was done on 110 assorted trees. The surveyed trees were divided into tree strata (low trunk, high trunk and canopy). In each stratum, scores were given (one to three) for all of the occurring epiphytic species according to its abundance. We listed 49 vascular epiphytic species (16 Pteridophyta, 23 Liliopsida and 10 Magnoliopsida) from 28 genera spread into 12 families, however only 34 species were found for the quantitative survey. The richest families were Orchidaceae, Polypodiaceae and Bromeliaceae, while Pleurothallis, Tillandsia and Oncidium made up the richest genera. Areas presenting the closest floristic similarity with this survey are located in the Curitiba County, state of Paraná, Brasil. For the quantitative survey, Microgramma squamulosa (Kaulf.) de la Sota, Pleopeltis angusta Humb. & Bonpl. ex Kunth, Peperomia catharinae Miq.and Polypodium hirsutissimum Raddi were the most important species. The number of species found for single host-trees ranged from zero to 13 while scores for abundance (VA) ranged from zero to 24. The canopy presented the highest abundance with a VA equal to 622 (high trunk = 308 and low trunk = 110).
Vascular epiphytes; floristic composition; vertical distribution; Araucaria forest
